1. Field of the Invention
The present invention relates to a molding material and a liquid ejection flow path member using the same.
2. Description of the Related Art
An ink jet recording apparatus involves relatively low running costs, is capable of being miniaturized, and can easily be adapted to color image recording with a plurality of inks, and so it is widely used in, for example, computer-related output equipment as a commercial product.
In recent years, there has been a demand for developing an ink jet recording head having a longer recording width so as to make it possible to record a high-definition image at higher speed. Specifically, an ink jet recording head having a recording width of from 4 inches (10.2 cm) to 12 inches (30.5 cm) in length is required. As a method for realizing an ink jet recording head having a long recording width, for example, Japanese Patent Application Laid-Open No. H05-24192 proposes a method of arranging a plurality of recording element substrates each having a moderate length on a support member to realize an ink jet recording head having a long recoding width as a whole.
In the method described in Japanese Patent Application Laid-Open No. H05-24192, the support member is required to have a high flatness and a low coefficient of linear expansion to cause no stress to a substrate such as Si. In addition, the support member is required to have high ink resistance. The reason for this is that if a material of the support member is dissolved in an ink, ejection performance is lowered, and deposit may occur in some cases to block an ejection orifice. An example of a representative material having these properties includes alumina. However, it is expensive to form a large-sized part with alumina. On the other hand, if a resin molding material disclosed in Japanese Patent Application Laid-Open No. 2011-173970 or No. 2009-155370 is used to cheaply produce the support member, the coefficient of linear expansion and ink resistance thereof are not always sufficient.
In addition, if an epoxy resin is used as a material of the support member in view of chemical resistance, it is necessary to increase the addition amount of filler for achieving a coefficient of linear expansion comparable with alumina. However, if the addition amount of the filler is increased, a mixture thereof becomes finely granular or powdery such as powder, and so it is impossible to uniformly mix the epoxy resin with the filler. On the other hand, even if the amount of the filler to be added is reduced to uniformly mix such materials, the epoxy resin expands upon extrusion under heating upon transfer molding, and the viscosity of the epoxy resin is lowered, and so surface roughening in which the epoxy resin is separated from the filler occurs, and surface accuracy cannot be ensured.